Dental engine



Nov. 15, 1927.

1,649,181 A. F. PIEPER DENTAL Enema Filed July 24, 1922 IN VENTOR.

Patented Nov. 1%, i229.

ALPHONSE F. PIEPER, OF ROCHESTER, NJE'W YORK.

DENTAL ENGINE.

Application filed July 24:,

This invention relates to dental engines and more particularly to the tool carrying arm mechanism thereof,one object of the invention bein to provide a simple, practical and inexpensive mechanism of this. character in which the weight of the arm portions is effectively counterbalanced to render the tool more easy to manipulate and convenient in use. Another object is to provide a mechanism of this type particularly adapted for use in a dental engine ofthe simple, treadle operated variety, to afford a simple ellicient and convenient tool arm mechanism for the latter. Still a further object is to provide a mechanism having in combination with the above advantages the feature of being cacable of folding into small space when not in use. To these andother ends the invention resides in certain improvements and combinations of parts all as will hereinafter be more fully described, the uovelfeatures be ing pointed out in the claims at the end of the specification.

1n the drawings:

Figure 1 is a side elevation of a dental engine embodying the present invention;

Figure 2 is an enlarged view of portions shown in Figure 1;

Figure 8 is a top plan view of the portion shown in Figure 2;

Figure a is a sectional view on the line d*i of Figure 3. 1

Similar reference numerals throughout the several views indicate the same parts.

The invention is embodied in the present instance in a dental engine combining tool carrying arm portions of any suitable variety, preferably of the general type disclosed in Letters Patent to O. H. Pieper and A. F. Pieper No. 1340908, granted May 25, 1920, for a dental engine, with a variety of simple treadle operated driving means and supporting standard well known in the art and employed where power operated engines are not available or desired, asfrequently the case for example in schools of dental instruction. The invention comprises the combina tion with such apparatus of means for counterbalancing the weight of the tool arm and thus atfords a simple and inexpensive treadle operated type of dental engine hav ing an efi'ective and convenient tool arm mechanism supporting the tool so that it respends lightly and easily to the movements 1922. Serial No. 5772032.

of the operators hand and contributes to etficiency and convenience in use.

Referring more particularly to the drawings there is shown at 5, Figure 1, a base carrying a standard 6 on which is rotatably supported a grooved pulley 7 having a fiex ible driving member or belt 8 passing around the same and upwardly over the top of the standard for driving the tool, as more fully described hereafter. There is pivotally supported on the base, as at 9, a foot treadle 10 pivotally connected at its inner end 11 with a link 12 rotatably connected at its opposite end with a crank arm 13 fixed to pulley 7 for rotating the latter.

Standard 6 is extended upwardly above the pulley and provided with a socket portion 14 in which is received a tubular section 15 in the upper end of which is fixed, as by means of a screw 16, "a rod section 17 provided at its upper end with a head portion 18 P forming the top of the standard.

A tool arm 19 is pivotally connected with, as at 20, and supported by the standard head 18, the arm having pivotally connected with its other end an outer arm section 21 the end of which carries a tool holding hand-piece 22. Head 18, the point of pivotal connection of the arm portions 19 and 21 and the hand-piece are provided with pulleys 23, 24, and 25, respectively, around which the flexible driving member 8 is passed, so that in any position of the arms and toolthe latter is driven by operation of the foot treadle 10. The above preferred form of arm and tool holder construction is as already stated shown and described in detail in the said letters patent, and as the particular construction of these portions forms no part of the present invention, a more detaileddescription thereof herein is unnecessary.

In order to counterbalance the weight of the arm portions and support the same on the standard so that the tool may be lightly and freely manipulated in use, unencumbered by the w ight of the arm, there is provided a balancing means, comprising preferably, a pair of members pivotally connected with each other at a point spaced above the pivotalsupport of the arm 19,

the one being supported by the standard and the other which is of a resiliently extensible character, adapted for attachment to the arm. One of these members in the present instance is in the form of a curved bracket member 26 fixed at its lower end in a clip 27 which slidably embraces the standard rod 17 and is fixed in adjusted position thereon as by means of a screw 28. The bracelet member 26 extends upwardly above and preferably slightly to the rear of the top of the standard or, more specifically, the center 20 of pivotal connection of the tool arm with the standard. To the upper end of this member 26 is pivotally connected, as at 29, one end of the other member indicated generally at 30, comprising a section 31 pivoted as stated on member 26 and comprising adjacent its other end a tubular portion or sleeve 32. Preferably one end of the latter is internally threaded and engaged with the threaded end 33 of the section 31. Telescopically carried in the tubular portion 32 is a section 34 in the form of a rod guided with reference to portion 32 by inwardly turned end walls 35 on the latter and by a head 36 in the form of a nut threaded on the end of section 34 and slidably engaging the inner walls of the tubular section 32. Coiled within the latter about the section 34 is a compression spring 37 which resiliently resists the telescopic extensible movement of the sections 31 and 34. The outer end of the latter is formed for detachable engagement with the tool arm, being in the present instance provided with a hook 38 engageable with a tool-rest 39 carried by the arm 19 for sustaining the hand-piece 22 when not in use. A curved leaf spring 40 is preferably carried by the standard head 18 for engagement as a stop or buffer with the tool arm when the latter is folded against the standard.

It is apparent from the above description of the construction that the engagement of the counter-balancing member 30 with the tool arm serves to sustain the latter in the outwardlydirected position shown in Figures 1 and 2 and yieldably resist its downward movement by reason of the spaced relation of the center of pivotal support of the arm on the standard and the point of pivotal connection of the counter-balance members 26 and 30. In other words downward movement of the tool arm causes its point of connection with the counter-balance member 30 to move away from the pivot 29 of the latter and therefore to extend the section 31 and 34 and compress spring 37. The degree or resistance of the latter to the downward movement of the tool arm may be regulated by adjusting clip 27 on the standard and thereby adjusting the distance between the pivotal points 20 and 29. The counter-balancingmeans may be readily detached from the tool arm as may be desired for folding the latter parallel with the standard when not in use. While simple, practical and inexpensive in construction the counter-balancing means is convenient to adjust as described and effectively supports and counterbalances the weight of the tool arm portions so as to leave the tool free for manipulation in a light and convenient mannor in use. and the engine as a whole combines simplicity and economy of driving and supporting means with an efficient tool arm mechanism advantageously supported and counter-balanced as described.

I claim as my invention:

1. The combination with a dental engine having a support and a tool arm pivotally connected with the latter for movement about a given center, of counter-balancing means for the arm comprising a bracket member adjustably fixed on the support and resiliently extensible telescoping portions detachably connected with the arm and secured to the bracket member at a point spaced from said center.

2. The combination with a dental engine having a support and a tool arm pivotally connected with the latter for movement about a given center, of eounterbalancing means for the arm comprising a bracket member fixed on the support a member having longitudinally telescoping sections coimected with the bracket member at one side of said center and with said arm respectively, and spring means yieldably resisting telescopic extension of said sections.

3. The combination with a dental engine having a support, a tool arm pivotall connected with the latter for movement a out a given center, and a tool rest on said arm, of eounterbalancing means for the arm comprising a member secured to said support and a second member provided with resiliently extensible sections one of which is pivotally connected with the first member at a point spaced from said center and the other formed for detachable engagement with said tool rest.

4. The combination with a dental engine having a supporting standard and a tool arm pivotally connected with the latter adjacent its top, of a bracket adjustably fixed on said standard and extending over the top thereof, a member having extensible sections one of which is pivotally connected with said bracket above the standard and the other formed for detachable engagement with said arm, and spring means resisting extensible movement of said sections.

5. The combination with a dental engine having a supporting standard and a tool arm pivotally connected with the latter ad- 'acent its top, of a bracket fixed on said standard and having an end extending above said arm pivot, and a member pivotally connected with said bracket end and comprising resiliently extensible sections, the outer of which is detachably connected with said arm.

ltll) end and the other detachably connected with said" arm, spring means resisting extension 10 of said sections to resiliently support said arm, and a resilient rest fixed on said support for supporting said arm when the latter is detached from said member and lowered to inoperative position.

ALPHONSE F. PIEPER. 

